Re: Preventing SSH timeouts . Some clarification needed

[query <query.cdac@xxxxxxxxx>]

2010/6/8 Michal Nazarewicz <mina86@xxxxxxx>:
>> 2010/6/8 Michal Nazarewicz <mina86@xxxxxxx>:
>>> Are you sure it's not because of some NATing which may have a shorter
>>> timeout then the one used by SSH's keep alive?
>
> query <query.cdac@xxxxxxxxx> writes:
>> I am not 100% sure but during the connection dropout  time , the CPU
>> is 100% busy as shown
>> by our own reporting utility.  Reg NAT ing , I don't think so those
>> hosts are behind NAT
>> as there was no requirement like that for those hosts to access
>> Internet .  Anyway , I will
>> confirm regarding this from the network-admin .
>>
>> P.S: Is there is any utility that can tell us whether we are behind
>> NAT or not .
>
> If “ifconfig” on one host gives you different IP addresses then the
> other host see as incoming IP then you are behind NAT.
>

Sorry , I failed to understand the above statement . But I have
something in mind , I will try it tomorrow .
>From the source machine , I send a packet to remote host on a
different network   . Now If I  capture packet on the remote host and
it comes out to be different ip address than the source host , then
probably I am behind NAT.  These hosts are having private ip address.

Will it help to help me know whether I am behind NAT ?




> There may be some other services that close the connection like
> firewalls and some such.  You should consult if there are any on the
> path and whether thous could drop connections with your network
> administrator.
>
> Also Glynn's suggestion of making keep alive timeout shorter may work.
>
> I find it hard to believe that high CPU usage could cause connection
> dropping unless you have some *really* busy machine but then you should
> consider upgrading hardware or rethinking what services those serves
> provide.

These hosts are not providing any Internet service and mainly
responsible for processing around Gigabits of data . The processing
continues for around 24 hours ,
During the processing , it utilizes around 100% CPU for around 4 hours
and the connection drop happened during that time . Not sure what
processig goes on during the time which takes all the CPU . The user
we are talking here is the user under whom these processes runs .

Hope it helps to understand the scenario .
>
> --
> Best regards,                                         _     _
>  .o. | Liege of Serenly Enlightened Majesty of      o' \,=./ `o
>  ..o | Computer Science,  Michal "mina86" Nazarewicz   (o o)
>  ooo +--<mina86-tlen.pl>--<jid:mina86-jabber.org>--ooO--(_)--Ooo--
>
Thanks
Zaman
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